At medical sites, by photographing an affected part included in an internal organ, a skeleton, or the like by using an X ray or the like, various tests and diagnoses are made. In recent years, by applying digital technologies, a dynamic image (an image group configured by a plurality of frame images) in which a motion of an affected part is acquired by using an X ray or the like can be acquired relatively easily.
Thus, since a dynamic image of a subject area including a diagnosis target area can be acquired by using a semiconductor image sensor such as a flat panel detector (FPD), a pathological analysis and a diagnosis based on a motion analysis of a diagnosis target area or the like, which cannot be performed according to conventional still-image photographing and analysis using X-ray photographing, have been attempted. Particularly, in a dynamic-state analysis of a chest X-ray, supports for a diagnosis/treatment (CAD for an X-ray dynamic image) using a functional and quantitative analysis of a dynamic-state relating to a change in the density of the inside of a pulmonary field for each position inside the pulmonary field have been also reviewed.
As a method for the quantitative analysis described above, a technology has been proposed in which analysis information effective for a diagnosis is generated by analyzing a temporal change based on frame images of a dynamic-state image of the chest.
For example, in a technology disclosed in Patent Literature 1, the technology has been disclosed which generates a new image by continuously acquiring a plurality of X-ray images in a time series, setting a line at a desired position for each of the plurality of X-ray images, acquiring a pixel row aligned along the set line, and aligning acquired pixel rows in the order of a time series.
In addition, in a technology disclosed in Patent Literature 2, the technology for acquiring a moving amount by measuring the position of the diaphragm based on a dynamic image, acquiring relative ventilation information for each divided chest area by specifying a dynamic image at the time of maximal inhalation and a dynamic image at the time of maximal exhalation and using a pixel differential value, executing linear interpolation between CT images, generating a coronal image, a sagittal image, and a Raysum image, measuring the position of the diaphragm based on the Raysum image, executing position adjustment between frames of the dynamic images of which the respiratory levels match those of the CT images and the Raysum image generated based on the CT images, and overlapping the ventilation information with the coronal image and the dynamic image has been disclosed. In addition, a method for measuring the positions of the horizontal diaphragm and a pulmonary apex, acquiring a moving amount, and displaying the graph of the motion based on the moving amount has been disclosed.